1. Field of the Invention
This invention pertains generally to teaching devices designed for use at the elementary and secondary school level, and more particularly to such devices specifically designed to facilitate investigations of phenomena associated with the heat transmitting properties of various materials and with the nature of solar radiation at the earth's surface.
2. Description of the Prior Art
The art of measuring heat flow and the intensity of radiant energy is well established. Various devices have been developed specifically to facilitate investigations in these areas and are described in the patent literature. Examples of such U.S. patents are a precision type of isothermal calorimeter, Jackson, et al. U.S. Pat. No. 2,733,602, 1956; a continuous flow, steady state calorimeter, Oliver, U.S. Pat. No. 2,800,793, 1957; a precision power comparing calorimeter, Czerlinsky, et al., U.S. Pat. No. 2,911,824, 1959; a thermal emissivity device, Dudley, et al., U.S. Pat. No. 3,142,983, 1964; a calorimeter apparatus for measuring high intensity radiation, Soffer, et al., U.S. Pat. No. 3,483,747, 1969; and a heat sensor measuring device, Progelhof, et al., U.S. Pat. No. 3,605,490, 1971. These devices have been developed to perform specialized functions and in response to specific needs for greater precision. They are designed for use by skilled scientists and are too specialized, technically sophisticated, and expensive to be useful as teaching devices at the elementary and secondary school levels.
The need for a practical device for teaching the measurement of heat flow is increasing as schools respond to the importance of developing a better understanding of the nature of energy and the use of energy as an economic good. In particular, there is a need for students to understand the heat transmitting properties of the various materials and devices which are common to their energy use experiences. More than a matter of pure science, this knowledge is important to a student's ability to understand and constructively respond to the pressures caused by the depletion of national energy supplies and the opportunity represented by the developing use of solar energy.